PATHOMORPHOLOGIC AND IMMUNOFUNCTIONAL CHA RACTERIZATION OF GRAFT-VERSUS-HOST-INDUCED INJURIES IN NONLYMPHATIC TARGET ORGANS AFTER SOLID-ORGAN TRANSPLANTATION IN THE RAT MODEL

While acute graft-versus-host disease (GvHD) is implicated with delete rious morbidity and a high mortality rate following allogeneic bone ma rrow transplantation (BMTx), comparable complications after transplant ation of solid vascularized organs are apparently rare. However, as ob served for single cases after liver, spleen-pancreas, lung, and small bowel transplantation (SBTx) GvHD often progresses and reaches a letha l outcome if the involved immunological reactions lead to clinical man ifestation. The here presented study compared isolated SBTx with the i mpact of simultaneous parental SB + BMTx in a semiallogeneic model (P --> F1) on incidence and clinical course of GvHD and related injury of target organs such as liver, skin, and gastrointestinal tract. Grade and severity of GvH-mediated clinical and pathomorphological alteratio ns were directly proportional to the amount of transplanted immunocomp etent cells and the number of proliferating cells in GvH-associated ta rget organs, and indirectly proportional to the initial anti-parental NK- and T-cell activity of F1 recipients.